What is industrial valve lapping and how is it done?

Industrial valve lapping refers to the procedure that is used when the sealing surfaces of a valve are machined to a smooth finish with the use of a fine abrasive. Lapping is the finishing of a surface that has previously been subjected to  grinding.

The process seeks to level the surfaces where the components are seated and contact each other. Surfaces where metal is in direct contact with metal tend to wear hard. At the same time, it is very important that the seal between the surfaces is tight to prevent leakage.

The abrasive creates friction, which is essential for grinding. The appropriate abrasion is decided by the material of the valve seat, the required amount of material removal and the machine speed.


When performing industrial valve lapping, follow these steps:


  1. Prepare the valve seat by wiping it and remove moisture.
  2. Grind the surface lightly with a portable valve grinding machine using a fine or medium paper.
  3. Proceed with fine git. If deep scratches are present, use coarse grit. Continue until the surface is smooth and the process is finished.

With LarsLap portable valve lapping machines, users can carry out valve lapping in situ, e.g. in a power plant. That means that you save time and money by not having to dissemble your application, reducing the operational downtime.

LarsLap offers solutions in valve lapping for any application using  steam, gas or liquid. We also have excellent experience in valve maintenance for the nuclear industry. We provide  valve lapping machines for valves 10-1300 diameter.

If you want to know more about industrial valve lapping, please contact LarsLap!

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